Flattening method and flattening apparatus

Abstract

A flattening method, by utilizing the advantages of the CARE method and making up for the disadvantages, can perform removal processing of a surface of a workpiece at a sufficient processing rate and can provide a processed surface having enhanced flatness without leaving damage in the processed surface. A flattening method comprises at least two surface removal steps and at least two cleaning steps, the final surface removal step being a catalyst-referred etching step comprising immersing a workpiece in a processing solution containing at least one of hydrohalic acid, hydrogen peroxide water and ozone water, and bringing a surface of a catalyst platen into contact with or close proximity to a surface to be processed of the workpiece to process the surface, said catalyst platen having in a surface a catalyst selected from the group consisting of platinum, gold, a ceramic solid catalyst, a transition metal, glass, and an acidic or basic solid catalyst.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a flattening method and a flattening apparatus, and more particularly to a flattening method and a flattening apparatus for flatly processing a surface (surface to be processed) of a workpiece, such as a simple substrate consisting of SiC or GaN, a bonded substrate (epitaxial substrate) having a layer of SiC or GaN, or a substrate for use in MEMS (micro electro mechanical system).[0003]2. Description of the Related Art[0004]With the recent progress toward higher integration of semiconductor devices, the circuit interconnects are becoming finer and the distance between adjacent interconnects is becoming smaller. Especially when forming a circuit pattern by optical lithography with a line width of not more than 0.5 μm, a stepper requires a high flatness of imaging surface because of the small depth of focus. A CMP apparatus for carrying out chemical mechanical polishing (CMP) is known as a...

AI Technical Summary

Benefits of technology

[0036]According to the present invention, after carrying out at least one surface removal step to enhance the flatness of a surface to be processed of a workpiece, CARE (catalyst-referred etching) processing, which can flatly process the surface (surface to be processed) of the workpiece with high precision, is carried out in the final surface removal step. This makes it possible to process the workpiece at a sufficient processing rate while gradually enhancing the flatness of the surface to be processed and finally create a damage-free, very flat processed surface. The present invention thus makes it possible to increase the throughput while fully enjoying the merits of CARE.

Problems solved by technology

However, the CARE method, in which removal processing (etching) of a surface of a workpiece progresses through dissolution in a processing solution of a halogen compound produced by chemical reaction between a halogen radical and a surface atom of the workpiece, has the drawback that the processing rate is significantly low as compared to grinding, CMP, etc. which are commonly used in the manufacturing of a semiconductor device.

Thus, high-throughput processing is difficult with the CARE method.

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